Protein kinase C plays an outstanding part in the regulation of cellular processes which are closely connected with the physiological control of contractile, secretory and proliferative processes (see Y. Nishizuka, Nature, 308, 593-698/1984). The physiological activation of protein kinase C takes place via "a second messenger" resulting by a receptor-initiated breakdown of membrane-bound phosphatidylinositols.
The present invention is concerned with new bis-(1H-indol-3-yl)-maleinimide derivatives which are potent inhibitors of protein kinase C.